Surely we recognize that living things exist independent and outside of us without needing to lessen our own existence.
>Couldn't you make the analogous argument that the extinction of all life on Earth would be fine since it would have absolutely no effect on the vast majority of the universe?
I suppose you could but that's not what I said.
I agree though, we should get out on some new space vessels soon to buy some insurance and project ourselves into the far future.
even leaving out monkeys and apes, i think other animals like for example racoons can make it to the "sapient" level with time if humans would "release" the space back to the Nature. And i think we have only very slightest idea about birds and insects. Cro-Magnon has been i'd say a version 0.7 of sapience with major bugs and broken&missing features, and i'd not be surprised if the Nature had other versions in the works.
If I was going to bet on non-human sapience, though, I'd go with crows. Intelligence seems to be most effective if you combine it with social instincts to create culture. Crows do this already.